I was just watching a DVD of an old Bo Diddley concert and it occurred to me to wonder how the word "jam" came to mean "an informal musical session". Is it just because you jam in everyone that's available or is there more to it than that?

And why has it come to mean 'luck' too? As in "You jammy sod".

I think jam is simply a modification of jazz, meaning even less informal, having even less discipline, even more freedom of individual expression, than jazz.

Interesting question, Bob. I haven't heard of "jammy sod" at all, Cat. Is that a British term, Americans, or have I just not heard it?

Bob, Etymology online says this about "jam:"

"to press tightly," also "to become wedged," 1706, of unknown origin, perhaps a variant of champ (v.). Sense of "to cause interference in radio signals" is from 1914. Jazz noun meaning "short, free improvised passage performed by the whole band" dates from 1929, and yielded jam session (1933); perhaps from jam (n.) in sense of "something sweet, something excellent." Noun sense of "machine blockage" is from 1890, which probably led to the colloquial meaning "predicament," first recorded 1914.

However, I didn't understand the reference to "champ" because the only definitions of that word that I could find were either "to bite or chew vigorously" or as the abbreviation of "champion." Would "to wedge something in" come from that? They seem to relate "jam" to "jazz" because of jazz being "sweet," though I saw no sources for that.

"Jammy", when used to mean "lucky", is a British informal saying with overtones of jealousy on the part of the speaker; the inference is that the "jammy" person has done nothing to deserve his/her luck.

I wonder (pure speculation, of course) if the evolution of "jam" was similar to the evolution of "tight" . . . something so cool and fun and creative and wonderful that it's "tight" . . . like a jam session.

Curious. The original 1706 quotation is "The Ice jam'd", which I suppose fits the supposed sense jam = cham (dialectal) = champ, if the ice was clashing and biting in the Arctic Sea. But the first use as a transitive verb is from De Foe in 1719, "The Ship... stuck fast, jaum'd in between two rocks", which fits the sense but makes me wonder about his pronunciation. You don't normally get that a/au fluctuation before m.

Now the evidenceless derivation of jam (session) from 'sweet' is another of those jumps in meaning that makes me look sympathetically on the Wolof theory: quite a few jive terms (hepcat, dig, honky, guy) don't make any sense in terms of English etymologies, so they just might be African borrowings. Or we're missing some process that was going on to give the jumps.

The Northern equivalent of jammy seems to be spawny, when you mean lucky. How common is that?

A Newcastle funny magazine, Viz Comic, has a character called Spawny Git.

I'd never come across "spawny" before. A cursory Google search brings up a UK slang dictionary at http://www.peevish.co.uk/slang/s.htm where it is simply defined as "lucky". A Swedish site at http://www.fiskbasen.se/index759.html says:

quote:

The name Spawny fish designates fish (especially Haddock but also Cod, Saithe and Whiting) whose stomachs are full of herring spawn.

Somehow I suspect that is not the usual meaning! Many other sites tended to be blogs reporting football matches; "Arsenal got a spawny goal" for example.

Another site, http://www.slangsite.com/slang/S.html introduced me to another word;

quote:

Spong: One who encounters great good luck, despite their own incredible stupidiy or clumsiness. Contraction of spawny and mong.
Example: Toby spilled his drink on that girl's top, and then she went back to his place to take it off to dry. The spong!

Now that is a word I look forward to using in conversation!

Oddly, the site doesn't define "spawny".